Display screen or portion thereof with transitional graphical user interface



FIG. 1 is a front view of the first image in a sequence of a displayscreen or portion thereof with transitional graphical user interface,showing our new design in a first embodiment;

FIG. 2 is a front view of the second image thereof;

FIG. 3 is a front view of the third image thereof;

FIG. 4 is a front view of the first image in a sequence of a displayscreen or portion thereof with transitional graphical user interface,showing our new design in a second embodiment;

FIG. 5 is a front view of the second image thereof; and,

FIG. 6 is a front view of the third image thereof.

The appearance of the transitional graphical user interface sequentiallytransitions between the images shown in FIGS. 1-3 and 4-6 . The processor period in which one image transitions to another forms no part of theclaimed design.

The broken lines showing the display screen or portion thereof in FIGS.1-3 and the alternate display screen or portion thereof in FIGS. 4-6form no part of the claimed design. The remaining broken lines showportions of the transitional graphical user interface that form no partof the claimed design.

CLAIM The ornamental design for display screen or portion thereof withtransitional graphical user interface, as shown and described.